1. Field of the Invention
The present invention relates to a compact cylindrical radial gap type motor having a rotor comprised of permanent magnets, and more particularly, to a DC brushless motor in which the motor characteristics are improved by appropriate establishment of the form of the salient poles for a motor with a concentrated winding armature structure using a bobbin for each of the salient poles, said salient poles having a distributed structure.
2. Description of the Prior Art
Patent Application 306115 of 1998 describes a laminated, inner rotor type brushless DC motor structure in which the armature is constructed of a ring section and multiple salient pole sections, where the length of each salient pole in the axial direction is practically the same as the length of its opposing rotor magnet.
The invention described in Japanese Patent Application 306115 of 1998 does not explain the dimensional relationship between the lead winding section and the opposing section of the salient pole magnet, nor does it explain the dimensional relationship between the width in the circumferential direction of the salient pole and the rotor magnetic pole pitch. Accordingly, it has the drawback that it does not clearly indicate which shape of salient pole improves the motor efficiency. As a result, even though a unique armature structure is presented, there is the drawback that a suitable effect cannot be obtained.